Connector for securing ultrasound catheter to transducer

ABSTRACT

An ultrasonic system includes an ultrasound transducer housing, an ultrasonic catheter, and a transducer mechanism. The ultrasound transducer housing contains a transducer horn configured to be connected to a signal generator. The ultrasonic catheter includes an ultrasound transmission member having a proximal end and disposed in the lumen, a sonic connector that connects the proximal end of the ultrasound transmission member with the transducer horn, a control ring, and a nesting piece configured to selectively receive the sonic connector. The control ring is operatively coupled to the nesting piece to move the nesting piece. The transducer mechanism is configured to move from a first position to a second position, and wherein the transducer mechanism is configured such that movement of the transducer mechanism from the first position to the second position engages the control ring on the catheter to move the nesting piece.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/256,233, filed Sep. 2, 2016, now U.S. Pat. No. 10,349,964, which is acontinuation of U.S. patent application Ser. No. 14/169,009, filed Jan.30, 2014, now U.S. Pat. No. 9,433,433, which is a continuation of Ser.No. 12/831,883, filed Jul. 7, 2010, now U.S. Pat. No. 8,641,630, whichis a continuation of Ser. No. 11/192,749, filed Jul. 29, 2005, entitled“Connector for Securing Ultrasound Catheter to Transducer” (now U.S.Pat. No. 7,758,510), which is a continuation of Ser. No. 10/666,459,filed Sep. 19, 2003, entitled “Connector for Securing UltrasoundCatheter to Transducer” (now U.S. Pat. No. 6,942,620), each of which isincorporated by reference as though set forth fully herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention pertains to medical equipment, and moreparticularly, to a device and method for attaching an ultrasoundcatheter to an ultrasound transducer which prevents frequency shifts andminimizes the mechanical impact of the handling connection area during amedical procedure.

Description of the Related Art

A number of ultrasound systems and devices have heretofore been proposedfor use in ablating or removing obstructive material from blood vessels.Ultrasound catheters have been utilized to ablate various types ofobstructions from blood vessels of humans and animals. Successfulapplications of ultrasound energy to smaller blood vessels, such as thecoronary arteries, require the use of relatively small diameterultrasound catheters which are sufficiently small and flexible toundergo transluminal advancement through the tortuous vasculature of theaortic arch and coronary tree. These ultrasound catheters incorporate avery small diameter ultrasound transmission member which extends throughsuch catheters. The proximal end of the ultrasound transmission memberis typically connected to an ultrasound transducer via a sonicconnector.

The attachment of the ultrasound transmission member to an ultrasoundtransducer plays a very important role in ultrasound energy propagation.The attachment region needs to be accurately aligned and free ofmechanical stress and other interfaces. For example, undesirable stressat the attachment region can be caused by pressing upon, pushing,pulling, torquing, bending or bumping the attachment region during useof the ultrasound catheter. In addition, it is preferable for the sonicconnector to be free from any interface (i.e., contact) with any othercomponent during energy transmission. Otherwise, such stresses andinterfaces can negatively impact the propagation of ultrasound energythrough the ultrasound transmission member. Contact of the sonicconnector with any other part of the catheter housing during thedelivery of ultrasound energy might also cause a shift in frequency andimpact performance.

Thus, there still exists a need for an improved connection of theproximal end of the ultrasound transmission member to an ultrasoundtransducer.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improvedconnection between the ultrasound catheter and the ultrasoundtransducer.

It is yet another object of the present invention to improve thepropagation of ultrasound energy by limiting and minimizing the impactof undesirable external forces.

In order to accomplish the objects of the present invention, there isprovided an ultrasound system and method of using the ultrasound systemduring a medical procedure. The ultrasound system has an ultrasoundtransducer having a transducer housing and a horn provided at the distalend of the transducer housing, an ultrasound transmission member, asonic connector that is connected to the horn and the proximal end ofthe ultrasound transmission member, and a catheter knob having aproximal end that is coupled to the distal end of the transducerhousing. The catheter knob has a proximal bore that houses the sonicconnector. The system also includes a nesting piece that is retainedinside the proximal bore of the catheter knob. The nesting piece can bemoved from a first position where the sonic connector is received insidethe nesting piece to a second position where the sonic connector isseparated from the nesting piece when ultrasound energy is beingpropagated through the ultrasound transmission member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an ultrasound system according to oneembodiment of the present invention.

FIG. 2 is a cross-sectional view of the Y-connector and catheter knob ofthe system of FIG. 1.

FIG. 3 is a cross-sectional view of the Y-connector, the catheter knob,the slide collar assembly and the transducer housing of the system ofFIG. 1 with the slide collar assembly in the non-supporting position.

FIG. 4 is a cross-sectional view of the Y-connector, the catheter knob,the slide collar assembly and the transducer housing of the system ofFIG. 1 with the slide collar assembly in the supporting position.

FIG. 5 is an exploded perspective view of some of the elements of theslide collar assembly of the system of FIG. 1.

FIG. 6 is an assembled perspective view of the elements of FIG. 5.

FIG. 7 is an exploded perspective view of the catheter knob of thesystem of FIG. 1.

FIG. 8 is an assembled perspective view of the catheter knob of FIG. 7.

FIG. 9 is a perspective view of the system of FIG. 1 with the slidecollar assembly in the non-supporting position.

FIG. 10 is a perspective view of the system of FIG. 1 with the slidecollar assembly in the supporting position.

FIG. 11 is a perspective view of the catheter knob of the system of FIG.1 with the slide collar assembly in the non-supporting position.

FIG. 12 is a perspective view of the catheter knob of the system of FIG.1 with the slide collar assembly in the supporting position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following detailed description is of the best presently contemplatedmodes of carrying out the invention. This description is not to be takenin a limiting sense, but is made merely for the purpose of illustratinggeneral principles of embodiments of the invention. The scope of theinvention is best defined by the appended claims. In certain instances,detailed descriptions of well-known devices, compositions, components,mechanisms and methods are omitted so as to not obscure the descriptionof the present invention with unnecessary detail.

FIG. 1 illustrates an ultrasound system according to the presentinvention for use in ablating and removing occlusive material inside thevessel of an animal or human being. The ultrasound system includes anultrasonic catheter device 10 which has an elongate catheter body 12having a proximal end 14, a distal end 16, and defining at least onelumen extending longitudinally therethrough. The ultrasound catheterdevice 10 is operatively coupled at its proximal end 14, by way of aY-connector 18, a catheter knob 20, and a slide collar assembly 22, toan ultrasound transducer housing 24 As shown in FIGS. 3-4, an ultrasoundtransducer 34 is housed inside the transducer housing 24. The ultrasoundtransducer 34 is connected to a signal generator 26, which can beprovided with a foot actuated on-off switch 28. The signal generator 26can be supported by an IV pole 27. When the on-off switch 28 isdepressed, the signal generator 26 sends an electrical signal to theultrasound transducer 34, which converts the electrical signal toultrasound energy. Such ultrasound energy subsequently passes throughthe catheter device 10 and is delivered to the distal end 16.

Referring also to FIGS. 2-4, an ultrasound transmission member 32extends through the lumen of the catheter 10 from the distal end 16 tothe proximal end 14. The ultrasound transducer 34 is coupled via a sonicconnector 36 (described in greater detail below) to the ultrasoundtransmission member 32, so that the ultrasound energy can be passedthrough the sonic connector 36 and the ultrasound transmission member 32to be delivered to the distal end 16 of the catheter 10. A guidewire 30,which can be any conventional monorail or over-the-wire guidewire, maybe utilized in conjunction with the catheter 10 in a manner that iswell-known in the catheter art.

The frontal portion of the Y-connector 18 is connected to the proximalend 12 of the catheter 10 using techniques that are well-known in thecatheter art. An injection pump (not shown) or IV bag (not shown) can beconnected, by way of an infusion tube (not shown), to an infusion portor sidearm 40 of the Y-connector 18. The injection pump can be used toinfuse coolant fluid (e.g., 0.9% NaCl solution) into and/or through thelumen of the catheter 10. Such flow of coolant fluid may be utilized toprevent overheating of the ultrasound transmission member 32 extendinglongitudinally through the lumen of the catheter 10. Such flow of thecoolant fluid through the lumen of the catheter 10 serves to bathe theouter surface of the ultrasound transmission member 32, therebyproviding for an equilibration of temperature between the coolant fluidand the ultrasound transmission member 32. Thus, the temperature and/orflow rate of coolant fluid may be adjusted to provide adequate coolingand/or other temperature control of the ultrasound transmission member32. In addition to the foregoing, the injection pump may be utilized toinfuse a radiographic contrast medium into the catheter 10 for purposesof imaging.

Examples of iodinated radiographic contrast media which may beselectively infused into the catheter 10 via the injection pump arecommercially available as Angiovist 370 from Berlex Labs, Wayne, N.J.and Hexabrix from Malinkrodt, St. Louis, Mo.

The proximal end of the ultrasound transmission member 32 is attached tothe sonic connector 36 which is configured to effect operative andremovable attachment of the proximal end of the ultrasound transmissionmember 32 to the distal horn 42 of the ultrasound transducer 34. Thesonic connector 36 is preferably configured and constructed to permitpassage of ultrasound energy through the ultrasound transmission member32 with minimal lateral side-to-side movement of the ultrasoundtransmission member 32 while, at the same time, permitting unrestrictedlongitudinal forward/backward vibration or movement of the ultrasoundtransmission member 32.

The ultrasound transmission member 32 may be formed of any materialcapable of effectively transmitting the ultrasonic energy from theultrasound transducer 34 to the distal end 16 of the catheter 10,including but not necessarily limited to metal, plastic, hard rubber,ceramic, fiber optics, crystal, polymers, and/or composites thereof. Inaccordance with one aspect of the invention, all or a portion of theultrasound transmission member 32 may be formed of one or more materialswhich exhibit super-elasticity. Such materials should preferably exhibitsuper-elasticity consistently within the range of temperatures normallyencountered by the ultrasound transmission member 32 during operation ofthe catheter 10. Specifically, all or part of the ultrasoundtransmission member 32 may be formed of one or more metal alloys knownas “shape memory alloys”. Such super-elastic metal alloys are well-knownin the art and will not be described in any further detail herein.

The proximal end of the Y-connector 18 is attached to the distal end ofthe catheter knob 20 by threadably engaging the proximal end of theY-connector 18 inside a threaded distal bore 44 at the distal end of thecatheter knob 20. O-rings 46 are provided in the threaded distal bore 44to minimize transverse vibrations. The proximal end of the catheter knob20 receives the extension 70 of the transducer housing 24 and issupported by the slide collar assembly 22. The slide collar assembly 22is positioned over the distal end of the transducer housing 24, and hasa non-supporting position where the slide collar assembly 22 isretracted towards the transducer housing 24; and has a supportingposition where the slide collar assembly 22 is extended to cover atleast a portion of the catheter knob 20. Thus, the slide collar assembly22 functions as a support member that is disposed on the transducerhousing 24 to support at least a portion of the catheter knob 20.

Referring also to FIGS. 5 and 6, the slide collar assembly 22 has aninner ring 50 (also referred to as collar 50) and an outer ring 52 (alsoreferred to as collar 52). The inner ring 50 has a bore 54 and alongitudinal slit 58 that extends through the length of the inner ring50. The distal portion of the bore 54 can be stepped as shown at 55 (seeFIG. 3) to function as a pushing surface that pushes a nesting piece 94(described below) in a distal direction as the inner ring 50 is movedfrom the non-supporting position to the supporting position. The outerring 52 also has a bore 56, and has a narrowed proximal end 57. Theinner ring 50 is retained inside the bore 56 of the outer ring 52 andabuts the narrowed proximal end 57 which acts as a stop to limit theproximal movement of the inner ring 50. Each of the inner ring 50 andthe outer ring 52 has an opening 60 and 62, respectively, that arealigned with each other and that are adapted to receive a locking pin64. A tubular inner sleeve 66 extends through the inside of the bore 54of the inner ring 50 to ensleeve the first extension 70 of thetransducer housing 24, as explained below. The sleeve 66 has a proximalsection 80 and an enlarged distal section 82. The inner ring 50 isnormally fitted around the proximal section 80 when the slide collarassembly 22 is in the non-supporting position, but the inner ring 50 isfitted around the distal section 82 when the slide collar assembly 22 isin the supporting position. Thus, providing the distal section 82 in anenlarged configuration allows for the inner ring 50 to achieve afriction-fit with the distal section 82, while the inner ring 50experiences a loose fit over the proximal section 80.

The transducer housing 24 has a cylindrical wall 68 having a distalextension that comprises two stepped cylindrical extensions 70 and 72extending from the distal end of the cylindrical wall 68. The firstextension 70 is attached to the distal end of the cylindrical wall 68,and has a greater outer diameter than the second extension 72 that isattached to the distal end of the first extension 70. A throughbore 76extends from the hollow interior 78 of the cylindrical wall 68 andthrough the extensions 70 and 72. The throughbore 76 can have the samediameter throughout its length. The second extension 72 is adapted to bereceived inside the proximal bore 90 of the catheter knob 20, while thefirst extension 70 is received inside the sleeve 66. In addition, anopening 84 is provided in the proximal section 80 of the sleeve 66 andis aligned with a corresponding opening 86 on the first extension 70,with the openings 84, 86 adapted to receive a locking pin 88 thatsecures the sleeve 66 to the first extension 70 at a fixed position.

A longitudinal slot 92 is provided on the sleeve 66. When the slidecollar assembly 22 is in the non-supporting position (i.e., inner ring50 positioned over the proximal section 80), the slot 92 is opened.However, when the slide collar assembly 22 is moved to the supportingposition, the inner ring 50 is positioned over the distal section 82 andcompresses the enlarged distal section 82 to close the slot 92. With theslot 92 closed, the sleeve 66 provides a frictional grip of the proximalend 91 of the catheter knob 20.

Referring now to FIGS. 2-4 and 7-8, the catheter knob 20 has a proximalbore 90 that can be sleeved over the second extension 72 in a mannersuch that the outer surface of the catheter knob 20 can be substantiallyflush with the outer surface of the first extension 70 (as best shown inFIGS. 3 and 4). The proximal bore 90 houses the sonic connector 36 and anesting piece 94. An elastic element 96, such as a spring, is seated inthe distal part of the proximal bore 90, and has one end carried on aprojection 98 provided at the distal end of the nesting piece 94. Thenesting piece 94 has a generally cylindrical configuration and has areceptacle 100 which functions to selectively retain the sonic connector36, as will be explained in greater detail below. In addition, a controlring 110 is positioned around the outer surface 112 of the catheter knob20. The control ring 112 cooperates with the nesting piece 94 to movethe nesting piece 94 in a reciprocal manner inside the proximal bore 90of the catheter knob 20, as explained below.

The nesting piece 94 has two opposite and aligned openings 102; only thetop opening 102 is shown in FIG. 7, but the bottom opening is the sameand is aligned on a straight line with the top opening 102. Similarly,the catheter knob 20 has two opposite and aligned channels 104; only thetop channel 104 is shown in FIG. 7, but the bottom channel is the sameand is aligned on a straight line with the top channel 104. In addition,the control ring 110 has two opposite and aligned openings 114. Thechannels 104 and the openings 102, 114 are aligned, as best shown inFIGS. 3 and 4. Two opposing pins 106 are provided, with each pin 106adapted to be fitted inside a corresponding set of channel 104 andopenings 102, 114, so as to couple the control ring 110 and the nestingpiece 94 as a unitary moving piece. The width of the channels 104 definethe distal and proximal limits of movement for the control ring 110 andthe nesting piece 94. The catheter knob 20 also has an annular flange116 provided about its outer surface 112 that also defines the distallimit of the movement of the control ring 110.

In use, the sonic connector 36 is shown in FIGS. 3-4 as connecting thetransducer horn 42 (e.g., with a threaded connection) with theultrasound transmission member 32. The sonic connector 36 is alwayslocated at a fixed position inside the proximal bore 90 of the catheterknob 20. When the slide collar assembly 22 is in the non-supportingposition shown in FIGS. 3, 9 and 11, the elastic element 96 normallybiases the nesting piece 94 in the proximal direction so that the sonicconnector 36 is received inside the receptacle 100 of the nesting piece94 to be supported by the nesting piece 94. The proximal movement of thenesting piece 94 will cause the pins 106 to move in the proximaldirection inside the channels 104, thereby causing the control ring 110to move proximally away from the flange 116. The outer ring 52 and theinner ring 50 are positioned completely over the proximal section 80 ofthe sleeve 66, with the narrowed proximal end 57 positioned adjacent thecylindrical wall 68 of the transducer housing 24.

When the slide collar assembly 22 is now moved from the non-supportingposition to the supporting position shown in FIGS. 4, 10 and 12, theuser pushes the outer ring 52 in the distal direction. The step 55 onthe distal end of the inner ring 50 engages the proximal end of thecontrol ring 110 and pushes the control ring 110 in the distaldirection. Movement of the control ring 110 in the distal direction willcause the pins 106 to move in the distal direction inside the channels104, thereby causing the nesting piece 94 to counter the bias of theelastic element 96 and move in the distal direction. As the nestingpiece 94 moves in the distal direction, the sonic connector 36 becomesfree from the receptacle 100 of the nesting bore 94. In addition, thedistal movement of the inner ring 50 will cause the inner surface of theinner ring 50 to engage the enlarged distal section 82 of the sleeve 66,which functions to close the slot 92 so as to frictionally grip theproximal portion 91 of the knob 20 when the slide collar assembly 22 isin the supporting position. The flange 116 and the width of the channels104 function as stops to limit the distal movement of the control ring110.

In the supporting position, the sonic connector 36 is not supported bythe nesting piece 94 so that the sonic connector 36 can be free from anycomponent or material interfaces, thereby promoting improved ultrasoundenergy propagation. The medical procedure can then be carried out whilethe slide collar assembly 22 is in the supporting position. Uponcompletion of the medical procedure, the above-described steps arereversed. In particular, the combined inner and outer rings 50, 52(slide collar assembly 22) are retracted in the proximal direction sothat they are now positioned over the proximal section 80 of the sleeve66. The bias of the elastic element 96 will push the nesting piece 94 inthe proximal direction so that the sonic connector 36 is received insidethe receptacle 100 of the nesting piece 94. In addition, the proximalmovement of the nesting piece 94 will cause the pins 106 to move in theproximal direction inside the channels 104, thereby causing the controlring 110 to move proximally away from the flange 116. Now, the catheter10 can be disconnected from the transducer 34.

While the description above refers to particular embodiments of thepresent invention, it will be understood that many modifications may bemade without departing from the spirit thereof. The accompanying claimsare intended to cover such modifications as would fall within the truescope and spirit of the present invention.

What is claimed is:
 1. An ultrasonic system, comprising: an ultrasoundtransducer housing containing a transducer horn configured to beconnected to a signal generator; an ultrasonic catheter that includes anultrasound transmission member having a proximal end and disposed in thelumen, a sonic connector that connects the proximal end of theultrasound transmission member with the transducer horn, a control ring,and a nesting piece configured to selectively receive the sonicconnector, the control ring operatively coupled to the nesting piece tomove the nesting piece; and a transducer mechanism configured to movefrom a first position to a second position, and wherein the transducermechanism is configured such that movement of the transducer mechanismfrom the first position to the second position engages the control ringon the catheter to move the nesting piece.
 2. The ultrasonic system ofclaim 1, wherein in the first position, the sonic connector is receivedinside the nesting piece, and in the second position, the sonicconnector is separated from the nesting piece.
 3. The ultrasonic systemof claim 1, wherein the ultrasonic catheter includes a catheter knobhaving a proximal end that is coupled to a distal end of the transducerhousing, the catheter knob having a proximal bore that houses the sonicconnector, the nesting piece being retained inside the proximal bore ofthe catheter knob.
 4. The ultrasonic system of claim 3, wherein thetransducer mechanism includes a slide collar assembly that is positionedover a distal end of the transducer housing, the slide collar assemblybeing movable between a non-supporting position and a support position,wherein when the slide collar assembly is in the non-supporting positionthe slide collar assembly is configured to not grip the catheter knob,and when the slide collar assembly is in the support position, the slidecollar assembly provides a frictional grip of the catheter knob.
 5. Theultrasonic system of claim 4, wherein the slide collar assembly includesan outer collar and an inner collar, the slide collar assembly movablefrom a retracted position where the outer collar and inner collar arespaced apart from the control ring, to an extended position where theinner collar engages and pushes the control ring.
 6. The system of claim5, wherein the inner collar has a first bore and the outer collar has asecond bore, with the inner collar received inside the second bore ofthe outer collar, and wherein the proximal end of the control ring ispositioned inside the first bore of the inner collar when the innercollar is in the extended position.
 7. The ultrasonic system of claim 6,wherein the slide collar assembly includes a sleeve partially retainedinside the first bore of the inner collar, the sleeve having alongitudinal slot, and wherein each of the inner collar and the outercollar has an opening, with a pin extending through the opening in theinner collar and the opening in the outer collar.
 8. The ultrasonicsystem of claim 7, wherein the longitudinal slot is opened when theslide collar assembly is in the non-supporting position and the slot isclosed when the slide collar assembly is in the supporting position, andwherein the sleeve grips the catheter knob when the slot is closed. 9.The ultrasonic system of claim 8, wherein when the slide collar assemblyis in the non-supporting position, the combined inner collar and theouter collar are retracted in a proximal direction so that the innercollar is positioned over the proximal section of the sleeve, wherein abias of an elastic element will push the nesting piece in the proximaldirection so that the sonic connector is received inside the nestingpiece.
 10. The ultrasonic system of claim 9, wherein the proximalmovement of the nesting piece will cause the control ring to moveproximally so that the ultrasonic catheter can be disconnected from thetransducer housing.
 11. The ultrasonic system of claim 4, wherein whenslide collar assembly is in the supporting position, the sonic connectoris not supported by the nesting piece so that the sonic connector can befree from any component or material interfaces, thereby promotingimproved ultrasound energy propagation.
 12. The ultrasonic system ofclaim 3, wherein the catheter knob has a longitudinal channel, andwherein each of the nesting piece and the control ring has an opening,with a pin extending through the opening in the nesting piece and theopening in the control ring, and the pin traveling within thelongitudinal channel, and further comprising an elastic element to pushthe nesting piece in the proximal direction so that the sonic connectoris received inside the nesting piece, and wherein the proximal movementof the nesting piece will cause the control ring to move proximally sothat the ultrasonic catheter can be disconnected from the transducerhousing.
 13. The ultrasonic system of claim 1, wherein the sonicconnector and the transducer horn are joined by a threaded connection.14. The ultrasonic system of claim 1, wherein the sonic connector andthe transducer horn are joined by a frictional connection.